Reexamination of Tropical Cyclone Heat Potential in the Western North Pacific
Reexamination of Tropical Cyclone Heat Potential in the Western North Pacific
复制标题
西北太平洋热带气旋热势的重新检查
DOI：
10.1002/2015jd024688
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发表时间：
2016
期刊：
影响因子：
--
通讯作者：
A.
中科院分区：
文献类型：
--
作者：
Wada;A.
热带气旋热势(TCHP)是从地表到26°C等温线深度的海洋热含量的量度，已被广泛用于热带气旋预报和气候学研究。鉴于海洋参考等温深度的重要性，本研究重新探讨了西北太平洋的TCHP及其与TCS的关系。原来的TCHP不适用于黑潮和黑潮延伸区，因为在26°C以下海面温度为零。因此，本研究提出了一种改进的TCHP，作为7-11月热带气旋季节大气环境中相对较弱的斜压条件下的新TCHP。根据2 m露点温度或低于24°C时的24°C来确定用于计算新的TCHP的替代海洋参考等温(TRef24)。我们考察了TCHP与2002年至2012年前6 h最佳路径中心气压变化的关系。相对较高的新TCHP与深海等温线深度和黑潮地区9-11月TRef24的减少有关。对台风Maemi(2003)、Songda(2004)和Roke(2011)的个例分析表明，TCS可以通过新TCHP高揭示的暖涡在琉球群岛周围加强/再发展，那里的原始TCHP相对较低。结果表明，新的TCHP可以作为地面和上层海洋层结附近大气温度和水汽引起的风致地表热交换过程引起的热带气旋加强的一个度量。
Tropical cyclone heat potential (TCHP), a measure of the oceanic heat content from the surface to the 26°C isotherm depth, has been widely used for tropical cyclone (TC) forecasting and climatological studies. This study reexamines TCHP and the relation to TCs in the western North Pacific in view of the importance of the oceanic reference isothermal depth. Original TCHP is not applicable around the Kuroshio and Kuroshio Extension regions because the value is zero where sea surface temperature is below 26°C. Therefore, this study proposes an improved version of TCHP as new TCHP under relatively weak baroclinic conditions in the atmospheric environment during the TC season from July to November. The alternative oceanic reference isothermal temperature (TRef24) used to calculate new TCHP is determined based on 2 m dew point temperature or 24°C when it is lower than 24°C. We examine the relationship between TCHPs and changes in best track central pressures during the previous 6 h from 2002 to 2012. Relatively high new TCHP is associated with deep oceanic isotherm depth and the decrease in TRef24 around the Kuroshio region from September to November. Case studies for Typhoons Maemi (2003), Songda (2004), and Roke (2011) reveal that TCs could intensify/redevelop around the Ryukyu Islands over warm eddies revealed by high new TCHP, where original TCHP is relatively low. The results indicate that new TCHP can be a metric for TC intensification caused by wind‐induced surface heat exchange processes associated with atmospheric temperature and moisture near the surface and upper ocean stratification.